Yokogawa PH450G Transmitter

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IM 12B6B5-E-E3rd edition

InstructionManual

YOKOGAWA

Model PH450G

pH and ORP Transmitter



Commissioning



PREFACE

Electrostatic discharge

The EXAxt transmitter contains devices that can

be damaged by electrostatic discharge. When

servicing this equipment, please observe proper

procedures to prevent such damage.Replacement components should be shipped in

conductive packaging. Repair work should be

done at grounded workstations using grounded

soldering irons and wrist straps to avoid

electrostatic discharge.

Installation and wiring

The EXAxt transmitter should only be used withequipment that meets the relevant IEC,

American or Canadian standards. Yokogawa

accepts no responsibility for the misuse of this

unit.

The Instrument is packed carefully with shock

absorbing materials, nevertheless, the

instrument may be damaged or broken if

subjected to strong shock, such as if the

instrument is dropped. Handle with care.

Do not use an abrasive or organic

solvent in cleaning the instrument.

Notice

Contents of this manual are subject to change

without notice. Yokogawa is not responsible for

damage to the instrument, poor performance of

the instrument or losses resulting from such, if

the problems are caused by:• Incorrect operation by the user.

• Use of the instrument in incorrect

applications.

• Use of the instrument in an inappropriate

environment or incorrect utility program.

• Repair or modification of the related

instrument by an engineer not authorised

by Yokogawa.

Warranty and service

Yokogawa products and parts are guaranteed

free from defects in workmanship and material

under normal use and service for a period of

(typically) 12 months from the date of shipment

from the manufacturer. Individual sales

organisations can deviate from the typicalwarranty period, and the conditions of sale

relating to the original purchase order should be

consulted. Damage caused by wear and tear,

inadequate maintenance, corrosion, or by the

effects of chemical processes are excluded from

this warranty coverage.

In the event of warranty claim, the defective

goods should be sent (freight paid) to the

service department of the relevant salesorganisation for repair or replacement (at

Yokogawa discretion). The following information

must be included in the letter accompanying the

returned goods:

• Part number, model code and serial number

• Original purchase order and date

• Length of time in service and a description

of the process

• Description of the fault, and the

circumstances of failure

• Process/environmental conditions that may

be related to the failure of the device.

• A statement whether warranty or non-

warranty service is requested

• Complete shipping and billing instructions

for return of material, plus the name and

phone number of a contact person who can

be reached for further information.

Returned goods that have been in contact with

process fluids must bedecontaminated/disinfected before shipment.

Goods should carry a certificate to this effect,

for the health and safety of our employees.

Material safety data sheets should also be

included for all components of the processes to

which the equipment has been exposed.

WARNING

CAUTION



TABLE OF CONTENTS

1. INTRODUCTION AND GENERAL DESCRIPTION ....................................................1

1-1. Instrument check............................................................................................1

1-2. Application ....................................................................................................1

2. GENERAL SPECIFICATIONS ....................................................................................2

3. INSTALLATION AND WIRING ..................................................................................4

3-1. Installation and dimensions ............................................................................4

3-2. Wiring ............................................................................................................6

3-3. Wiring the power supply ................................................................................8

3-4. Wiring the contact signals ..........................................................................10

3-5. Wiring the mA-output signals ......................................................................103-6. Wiring the sensor system ............................................................................11

3-7. Sensor wiring ..............................................................................................12

4. OPERATION OF EXAxt PH450G ............................................................................18

4-1. Main display functions ................................................................................18

4-2. Trending graphics ........................................................................................18

4-3. Zoom in on details ......................................................................................18

4-4. Information function ....................................................................................20

4-5. Setup calibration & commissioning ..............................................................20

4-6. Secondary-primary value display switch ......................................................20

4-7. Navigation of the menu structure ................................................................21

5. MENU STRUCTURE COMMISSIONING ................................................................23

5-1. Sensor setup ..............................................................................................23

5-2. Measurement setup ....................................................................................23

5-3. Temperature settings ..................................................................................23

5-4. Temperature compensation ........................................................................23

5-5. Calibration settings ......................................................................................25

5-6. Impedance settings ....................................................................................255-7. mA output setup ........................................................................................27

5-8. Contact output setup ..................................................................................29

5-9. Fail ..............................................................................................................31

5-10. Simulate ......................................................................................................31

5-11. Error configuration ........................................................................................33

5-12. Logbook configuration ................................................................................33

5-13. Advanced setup ..........................................................................................35

5-14. Display setup ..............................................................................................37

IM 12B6B5-E-E



6. CALIBRATION ......................................................................................................38

6-1. Calibration check with buffer solutions ......................................................38

6-2. Manual calibration mode ..........................................................................386-3. Automatic calibration mode ......................................................................38

6-4. Sample calibration mode ..........................................................................39

6-5. Temperature calibration ............................................................................39

6-6. ORP & rH calibration ................................................................................39

6-7. Operation of HOLD function during calibration ..........................................39

6-8. Contact output setput ..............................................................................39

7. MAINTENANCE ....................................................................................................41

7-1. Periodic maintenance ................................................................................417-2. Periodic maintenance for the sensor ........................................................41

8. TROUBLESHOOTING ............................................................................................43

8-1. General ....................................................................................................43

8-2. Calibration check ......................................................................................43

8-3. Predictive maintenance ............................................................................43

8-4. Poor calibration technique ........................................................................43

8-5. Error display and actions ..........................................................................43

9. QUALITY INSPECTION ........................................................................................44

10. SPARE PARTS ....................................................................................................48

11. SOFTWARE HISTORY ..........................................................................................49

APPENDICES ............................................................................................................50

Appendix 1 : Buffer tables ....................................................................................50

Appendix 2 : HART HHT (275/375) menu structure ..............................................51 Appendix 3 : Temperature compensation matrix ..................................................55

IM 12B6B5-E-E



The Yokogawa EXAxt PH450G is a transmitter

designed for industrial process monitoring,

measurement and control applications. This

instruction manual contains the information

needed to install, set up, operate and maintainthe unit correctly. This manual also includes a

basic troubleshooting guide to answer typical

user questions.

Yokogawa can not be responsible for the

performance of the EXAxt transmitter if these

instructions are not followed.

1-1. Instrument check

Upon delivery, unpack the instrument carefullyand inspect it to ensure that it was not

damaged during shipment. If damage is found,

retain the original packing materials (including

the outer box) and then immediately notify the

carrier and the relevant Yokogawa sales office.

Make sure the model number on the nameplate

affixed to the side of the instrument agrees with

your order. Example of the nameplate is shown

below.

Note! The nameplate will also contain the serial

number and any relevant certification

marks. Be sure to apply correct power to

the unit, as detailed on the nameplate.

1-2. Application

The EXAxt transmitter is intended to be used for

continuous on-line measurement of pH and/or

Redox in industrial installations. The unit

combines simple operation and microprocessor-based performance with advanced self-

diagnostics and enhanced communications

capability to meet the most advanced

requirements. The measurement can be used as

part of an automated process control system. It

can also be used to indicate operating limits of a

process, to monitor product quality, or to

function as a controller for a

dosing/neutralisation system.

Sensors should normally be mounted close to

the transmitter in order to ensure easy

calibration and peak performance. If the unit

must be mounted remotely from the sensors,

WF10 extension cable can be used, up to a

maximum of 50 meters (150 feet), with a BA10

junction box, and up 10 meters standard sensor

cable.

The EXAxt is delivered with a general purpose

default setting for programmable items (see

Chapter 5). While this initial configuration allows

easy start-up, the configuration should be

adjusted to suit each particular application. An

example of an adjustable item is the type of

temperature sensor used. The EXAxt can be

adjusted for a number of different types of

temperature sensors.

Details provided in this instruction manual are

sufficient to operate the EXAxt with all Yokogawa sensor systems and a wide range of

third-party commercially available probes. For

best results, read this manual in conjunction

with the corresponding sensor instruction

manual.

Yokogawa designed the EXAxt transmitter to

withstand industrial environments. It meets all

the CE regulatory standards. The unit meets or

exceeds stringent requirements (see section 2)

without compromise, to assure the user of

continued accurate performance in even the

most demanding industrial installations.

1

Figure 1-1. Nameplate

I N T R OD U C T I O

N A N D GE N E R A L D E S C R I P T I ON

1

1. INTRODUCTION AND GENERAL DESCRIPTION

IM 12B6B5-E-E



2. GENERAL SPECIFICATIONS OF EXAxt PH450G

A) Inputs specs : Dual high impedance input (≥ 1013Ω)

(under referance conditions)

B) Input ranges

pH : -2 to 16 pH

ORP : -1500 to 1500 mV rH : 0 to 100 rH

Temperature

- Pt1000 : -30 to 140ºC

- Pt100 : -30 to 140ºC

- 350Ω (DKK) : -30 to 140ºC

- 5k1 : -30 to 140ºC

- 6k8 : -30 to 140ºC

- PTC10k : -30 to 140ºC

- NTC 8k55 : -10 to 120ºC

- 3kBalco : -30 to 140ºC

C) Accuracy

pH input : < 0.01 pH

ORP input : < 1 mV

Temperature : < 0.3 ºC (≤ 0.4 ºC for Pt100)

mA output circuits : < 0.02 mA

Ambient temperature

influence : 100 ppm / ºC

Step respons : < 4 sec for 90% (pH 7 - pH 4)

D) Transmission signals

General : Two isolated outputs of 4-20 mA. DC with common negative. Maximum

load 600Ω. Bi-directional HART ® digital communication, superimposed on

mA1 (4-20mA) signal

Output unctions : Linear or Non linear (21-step table) output for pH, temperature, ORP or rH

Control function : PID control

Burnout function : Burn up (21.0 mA) or burn down (3.6 mA) to signal failure acc.

NAMUR NE43

Adjustable damping. Expire time

Hold : The mA-outputs are frozen to the last/fixed value during

calibration/commissioning

E) Contact outputs

General : Four SPDT relay contacts with display indicators

Switch capacity : Maximum values 100 VA, 250 VAC, 5 Amps.

Maximum values 50 Watts, 250 VDC, 5 Amps.

Status : High/Low process alarms, selected from pH, ORP, rH and temperature

Configurable delay time and hysteresis

Failure annunciation

Control function : On/Off, PID duty cycle or pulsed frequency control

Wash : Contact can be used to start manual- or interval time wash cycles

Hold : The contact is frozen to the last/fixed value during

calibration/commissioning

Fail : Contact S4 is programmed as fail-safe contact

2

IM 12B6B5-E-E



2

G

E N E R A L S P E C I F I C A T I ON S

3

IM 12B6B5-E-E

F) Temperature compensation

Function : Automatic or manual

Compensation to Nernst equation

Process compensation by configurable temperature coefficient, NEN6411

for water or strong acids/bases or programmable matrix

G) Calibration : Semi-automatic 1 or 2 point calibration using pre-configured NIST, US,

DIN buffer tables 4, 7 & 9, or with user defined buffer tables, withautomatic stability check

Manual adjustment to grab sample

H) Logbook : Software record of important events and diagnostic data readily available

in the display

I) Display : Graphical Quarter VGA (320 x 240 pixels) LCD with LED backlight and

touchscreen. Plain language messages in English, German, French,

Spanish and Italian

J) Shipping details

Package size : 293 x 233 x 230 mm (L x W x D) (11.5 x 9.2 x 9.1 inch)

Package weight : app. 2.5 kg (5.5lbs)

K) Housing : Cast Aluminim housing with chemically resistant coating;

Polycarbonate cover with Polycarbonate flexible window

: Protection IP66/ NEMA4X

Colour : Silver grey

PH450-A(D)-A : IP66 cable glands are supplied with the unit

PH450-A(D)-U : NEMA4X blind plugs are mounted in the unused cable entry holes

and can be replaced by conduit fittings as required

Pipe, Panel or Wall mounting using optional hardware

L) Power supply : 100-240 VAC (±10%). Max 10VA, 47-63Hz

12-24 VDC (±10%), max 10W

M) Regulatory compliance

EMC : Meets directive 89/336/EEC

Emission conform EN 55022 class A

Immunity conform IEC 61326-1

Low Voltage : Meets directive 73/23/EECConform IEC 61010-1, UL61010C-1 and CSA 22.2 No. 1010.1,

Installation category II, Pollution degree 2

Certification for cCSAus, Kema Keur and

FM Class 1, Div. 2, Group ABCD, T 6 for T a -20 to 55ºC

N) Environment and operational conditions

Ambient temperature: -20 to +55 ºC

Storage temperature: -30 to +70 ºC

Humidity : 0 to 90% RH (non-condensing)

Data protection : EEPROM for configuration data and logbook. Lithium cell for clock

Watchdog timer : Checks microprocessor

Power down : Reset to measurement

Automatic safeguard: Auto return to measuring mode when touchscreen is untouched for 10 min



3-1. Installation and dimensions

3-1-1. Installation site

The EXAxt 450 transmitter is weatherproof and

can be installed inside or outside. It should,

however, be installed as close as possible to the

sensor to avoid long cable runs between sensor

and transmitter. In any case, the cable length

should not exceed 50 metres (162 feet). Select

an installation site where:

• Mechanical vibrations and shocks are

negligible

• No relay/power switches are in the direct

environment

• Access is possible to the cable glands

(see figure 3-1)

• The transmitter is not mounted in direct

sunlight or severe weather conditions

• Maintenance procedures are possible

(avoiding corrosive environments) The ambient temperature and humidity of

the installation environment must be within

the limits of the instrument specifications.

(See chapter 2).

3-1-2. Mounting methods

Refer to figures 3-2 and 3-3. Note that the

EXAxt transmitter has universal mounting

capabilities:

• Panel mounting using optional brackets

• Surface mounting on a plate (using bolts

from the back)

• Wall mounting on a bracket (for example,

on a solid wall)

• Pipe mounting using a bracket on a

horizontal or vertical pipe

(maximum pipe diameter 50 mm)

Model Suffix Code Option code Description

PH450G pH / ORP transmitter

Power - A AC version (85…265 VAC)

- D DC version (9.6…30 VDC)

- A General purpose version- U FM certified

Options / SCT *1 Predefined Tagnumber (text only)

/ Q Quality and Calibration Certificate

/ UM Universal Mounting kit (panel, pipe, wall)

*1 If the tagnumber is predefined with the purchase, Yokogawa will inscript the tagplate with the

specified tagnumber, and program the tagnumber in the transmitter.

Model code

4

IM 12B6B5-E-E

3. INSTALLATION AND WIRING



3

144(5.67)

1 4 4 ( 5 . 6

7 "

)

2 4 . 5

( 1 " )

1 1 4 . 5

( 4 . 5

1 " )

27(1.06")

M20

min.185 (7.25)

m i n . 1

9 5 ( 7 . 7

5 )

138(5.43)

138(5.43)

M6

M6

M5

138

1 3 8

Figure 3-1. Housing dimensions and

layout of glands

Figure 3-2. Option /UM. Universal mounting

kit, panel mounting diagram

I N S T A L L A T I ON A N D WI R I N G

5

IM 12B6B5-E-E

Figure 3-3. Wall and pipe mounting diagram

80(3.15")

2x ø6.5(0.26")

4x ø10(0.4")

200(7.87")

70(2.75")

141.5(5.57")

2" ND. pipe

pipe mounting

(horizontal)

pipe mounting

(vertical)

wall mounting

OPTION /UM: Universal pipe/wall/panel mounting kit



3-2. Wiring

3-2-1. Preparation

Refer to figure 3-4. The relay contact terminals

and power supply connections are under the

screening (shielding) plate. These should be

connected first. Connect the sensor, outputs

and HART ® communication connections last.

To open the EXAxt 450 for wiring:

1. Loosen the four frontplate screws and swing

open the cover.

2. The upper terminal strip is now visible.

3. Remove the screen (shield) plate covering

the lower terminal strip.

4. Connect the power supply and contact

outputs. Use the three glands at the back

for these cables.

Always place the screen plate over the power

supply and contact terminals for safety reasons

and to avoid interference.

5. Put back (replace) the screen (shield) plate

over the lower terminals.

6. Connect the analog output(s), the sensor

inputs, and, if necessary, the HART ®

wiringand input contact.

7. Use the front three glands for analog output,

sensor inputs, contact input and HART ®

wiring (see figure 3-5).

8. Swing back the cover and secure it with the

four screws.

9. Switch on the power. Commission the

instrument as required or use the default

settings.

WARNING

Figure 3-4. Internal view of EXA wiring compartment

LCD

bracket

connector for (future) software updates input terminal block

protective shield bracketM20 glands

output

terminal block

6

IM 12B6B5-E-E

Note: PH450G-A(D)-U

The enclosure is provided with stoppers in stead of M20 cable glands for the unused holes.

These stoppers must be removed and replaced by FM approved conduit fittings in

accordance with good installation practice.

potentio-

meter



3

High voltage section

Contact(S1, S2)outputcables

mAcables

Contact(S3, S4)outputcables

SensorCables

Inputcontact

Powercable

Suitable for cables with an outside diameter between 7 - 12 mm (0.28 - 4.72”)

Figure 3-5. System configuration

I N S T A L L A T I ON A N D WI I R I N G

7

IM 12B6B5-E-E

3-2-2. Cables, Terminals and glands

PH450-A(D)-A

The PH450 is supplied with terminals suitable

for the connection of finished wires in the size

range of 0,13 to 2,5 sq.mm. ( 26 to 14 AWG).

The cable glandes supplied will form a tight seal

on cables with an outside diameter of 7 to 12mm (9/32 to 15/32 inches). Unused cable entry

holes must be sealed with cable glands

including the blind plugs supplied.

PH450-A(D)-U

The PH450 is supplied with terminals suitable

for the connection of finished wires in the size

range of 14- 26 AWG. The cable entry holes are

sealed with FM certified plugs. Prior to cable

entry the plugs can be removed with allen keysize 3/8” The cable conduit fittings can be

mounted in the holes of the housing as required.

The cable glands supplied with the unit will give

a tight seal on cables with outside diameter of

9/32 to 15/32 inches.



3-3. Wiring the power supply

3-3-1. General precautions

Make sure the power supply is switched off.

Also, make sure that the power supply is correct

for the specifications of the EXAxt and that the

supply agrees with the voltage specified on the

textplate.

Local health and safety regulations may require

an external circuit breaker to be installed. The

instrument is protected internally by a fuse. The

fuse rating is dependent on the supply to the

instrument. The 250 VAC fuses should be of the

“time-lag” type, conforming to IEC127.

Fuse ratings:

Power supply Fuse type

9.6-30VDC, 10W max 1A/250V, Slow

85-265VAC, 10VA max 0.5A/250V, Slow

Refer to the service manual for fuse replacement.

3-3-2. Access to terminal and cable entry

Terminals 1, 2 and 3 are used for the power

supply. Guide the power cables through the

gland closest to the power supply terminals. The

terminals will accept wires of 2.5 mm2 (14

AWG). Always use cable finishings if possible.

3-3-3. AC power

Connect terminal L1 to the phase line of the AC

power and terminal N to the zero line. See figure

3-8 for the power ground. This is separated

from input ground by a galvanic isolation.

3-3-4. DC power

Connect terminal 1 to the positive outlet and

terminal 2 to the negative outlet. Terminal 3 is

for the power ground. This is separated from

input ground by a galvanic isolation. A 2-core

screened cable should be used with the screen

connected to terminal 3. The size of conductors

should be at least 1.25 mm2

. The overall cable

diameter should be between 7 & 12 mm.

S1

S2

S4

S3

FRONT GLANDS REAR GLANDS

Sensor

outputsignals

HART

Contactoutput

Contactoutput

Power

Contact input

mA1

mA2

Figure 3-6. System configuration

8

IM 12B6B5-E-E



3

3-3-5. Grounding the housing

For the safety of the user and to protect the

instrument against interference, the housing

should always be connected to ground. This has

to be done by a large area conductor. This

cable can be fixed to the rear of the housing or

by using the internal ground connections using a

braided wire cable. See figure 3-8.

3-3-6. Switching on the instrument

After all connections are made and checked, the

power can be switched on from the power

supply. Make sure the LCD display comes on.

After a brief interval, the display will change to

the measured value. If errors are displayed or a

valid measured value is not shown, consult the

troubleshooting section (Chapter 8) before

calling Yokogawa.

Figure 3-7. Input and output connections

Figure 3-8-a. External grounding Figure 3-8-b. Internal grounding

63 66 65 61 22 21 12 14 13 15 16- + - + + - IN SHLD IN SHLD

INPUT 2

mA OUTPUTS

INPUT 1

62 11 17

LETEMPmA2

SHLD

CONTACT SENSOR(S)

REFER TO INSTRUCTION MANUAL FOR CONNECTIONS PH

IMP.LOW

IMP.LOW

mA1(+HART)

2N

1L

POWER-2 1 - z

FUSE: 5 m 25 T


9

IM 12B6B5-E-E

32 31 33 42 41 43 52 51 53 72 71 73

NC C NO NC C NO NC C NO NO C NC

S1 S2 S3CONTACTS S4

250V / 5AAC / DC

100VA / 50W

(fail-safe)



3-4. Wiring the contact signals


The contact output signals consist of voltage-

free relay contacts for switching electrical

appliances (SPDT). They can also be used as

digital outputs to signal processing equipment

(such as a controller or PLC). It is possible to usemulti-core cables for the contact in and output

signals and shielded multi-core cable for the

analog signals.

3-4-2. Contact outputs.

The EXAxt 450 unit’s four contacts (switches) that

can be wired and configured to suit user

requirements. Contact S4 is programmed as a

fail-safe contact. Please refer to section 5-7,

Contact output setup for functionality description.

Alarm (limits monitoring)

Contacts configured as "ALARM" can be

energized when limits are crossed.

Fail

Contacts configured as "FAIL" will be energized

when a fail situation occurs. Some fail situations

are automatically signaled by the internal

diagnostics (electronics) of the transmitter.

Others can be configured by the user (see

section 5-10 Error Configuration). By pressing

the "INFO" button on the main screen the user

is given an explanation as well as a remedy for

the current fail situation.

Always connect the fail contact to an alarm

device such as a warning light, alarm bell or

displayed on an annunciator.

* When a fail situation occurs which is related to the

parameter associated with the contact (pH, ORP,

rH or temperature) the contact will go to NC.

When the fail situation is not related to the

parameter associated with the contact the contact

will remain in the state it is currently in.

** Wash cycles do not influence other contacts.

When HOLD is enabled during wash, it is HOLD

that will set all contacts to NC.

3-5. Wiring the mA-output signals


The analog output signals of the EXAxt transmit

low power standard industry signals to

peripherals like control systems or strip-chart

recorders (Figure 3-6).

3-5-2. Analog output signals

The output signals consist of active current

signals of 4-20 mA. The maximum load can be

600 ohms on each.

It is necessary to use screening/shielding on the

output signal cables. Terminal 63 is used to

connect the shielding.

"ALARM" Contact "FAIL" Contact

Power Off NC NC

Power On NC NC

Alarm NO NC

Fail NC NO

Fail and Alarm NC* NO

HOLD** NC NC

10

IM 12B6B5-E-E



3

Jumper Settings Application & Sensor Connections

Normal pH sensors.

Glass sensor on Input 1.

Reference sensor on Input 2.

Special electrodes using 2 glass sensors.

13 17 15 16 (e.g. Pfaudler)

ORP (Redox measurement).

Metal sensor on Input 1.

Normal reference on Input 2.

ORP (pH compensated) or rH measurement

Metal sensor on Input 1.

pH glass (as reference) on Input 2.

Table 3-1. Impedance measuring jumpers

6 3 6

3

6 6 6

6

6 5 6

5

6 2 6

2

6 1 6

2 2 2

2

2 1 2

1 1

1 2

2

1 4

4

I N N

I m p .

I

m

p

L O W

L

O

W

I N N

1 3

3

1 7

7

1 5

5

1 6

6

I m p .

I

m

p

L O W

L

O

W

Figure 3-9.a. Jumper placement for low

impedance setting


Figure 3-9.b. Jumper holders in cover

11

IM 12B6B5-E-E

3-6. Wiring the sensor system

3-6-1. Impedance measurement jumper

settings

Impedance measurement is a powerful

diagnostic tool. In order to perform impedance

measurements it is important to have a good

jumper setting. The table and figure below willguide you to make the right setting.

Note! It is important to decide first which

application and which settings are appropriate

for the installation. This decision is best done

before the jumpers are installed, because the

cables will rest on top of the jumpers in their

installed positions.

Figure 3-9-a. shows the jumper positions related

to the types of measurement stated in Table 3-1.

For Low impedance the Hi and Lo should beshorted by a jumper. See drawing below.

When shipped, the default setting is set for pH

measurement (13 is shorted to become a low

impedance input). The second jumper can be

found in the cover of the EXAxt.



3-7. Sensor wiring

Refer to figure 3-10, which includes drawings

that outline sensor wiring.

The EXAxt 450 can be used with a wide range

of commercially available sensor types, both

from Yokogawa and other manufacturers. Thesensor systems from Yokogawa fall into two

categories; the ones that use a fixed cable and

the ones with separate cables.

To connect sensors with fixed cables, simply

match the terminal numbers in the instrument

with the identification numbers on the cable ends.

The separate sensors and cables are not

numbered, but instead use a color-codingsystem. The electrodes have a colored band

incorporated in the label on the connection cap:

• Red for measuring electrodes (both pH

and ORP)

• Yellow for reference electrodes

• Blue for combined sensors with both

measuring and reference elements in

the same body

• Green for temperature sensors

The recommended procedure is to color-code

each end of the cables to match the sensors

with the color strips provided with each cable.

This provides a quick way to identify the ends of

the cables belonging to a particular sensor when

they are installed.

3-7-1. Connection cable

The coaxial cable has two connections.

• Red to measuring element

• Blue to screen (shield)

The triaxial cable has three connections,

(it has an extra white wire termination)

these wires are connected:

• Red to measuring element

• Blue to reference

• White to screen (shield)

To connect the other sensor systems, follow the

general pattern of the terminal connections as

listed below:

Terminal Single Measurement (pH or Redox) Combined measurement (pH and Redox)

pH ORP pH and ORP pH and rH

11 Temperature 1 – Temperature 1 Temperature 1

12 Temperature 2 – Temperature 2 Temperature 2

13 Reference Reference Reference Reference

14 Liquid Earth Liquid Earth ORP ORP

15 pH ORP pH pH

16 Shield of nr 15 Shield of nr 15 Shield of nr 15 Shield of nr 15

17 Shield of nr 13 Shield of nr 13 Shield of nr 13 Shield of nr 13

Note!

• Secondary value is always temperature. For combined pH and Redox measurement, pH is the primary value and

Redox the tertiary value.

• For ORP measurement, temperature is not required for automatic temperature compensation

12

IM 12B6B5-E-E

core

shield

red

blue

Coaxial

red

blue

white

Triaxial



3

*

*

*

*

Green

Yellow

Red

Red

Blue

BlueBlue

Red

Black

Red

Cable markers

11 Temperature

12 Temperature

13 Reference

14 Solution ground

15 Glass (measure)

16 Shield

17 Shield

pH transmitter

Seporate electrodes for pH

measurement

11 Temperature

12 Temperature

13 Reference

14 Solution ground

15 Glass (measure)

16 Shield

17

11

12

13

14

15

16

FU20 four-in one sensor for pH measurement

Note:Connect cables to similary marked terminals:11 to 11, 12 to 12, etc.This configuration also enables combinedpH+ORP measurements

*

*

*

16 Shield

15 Glass (measure)

14 Solution ground

13 Reference

12 Temperature

11 TemperatureRedBlue

Green

RedBlue

Blue

Black

White17 Shield

Cable markers

Combined glass/reference electrode

for pH measurement

15 Glass (measure)

14 Solution ground

13 Reference

12 Temperature

11 Temperatureredblue

black

yellow

transparent

black (coax)16 Shield

17

Retractable sensor assembly PR20(Also PD20, PF20 & PS20)

Note:Connect cables to similary marked terminals:11 to 11, 12 to 12, etc.

Figure 3-10.a. Sensor wiring for pH measurement

Figure 3-10.b. Sensor wiring for combined (pH + Redox) measurement


13

IM 12B6B5-E-E

TC REF Liquid PH Comb ORP Comb Comb

Earth PH/REF ORP/REF PH/ORP

PH

PH + ORP





Remove

standard tule

3.11.b. Content of grommet set

3.11.a. Grommet set use

3-7-2. Sensor cable connection with

special grommet (450G- -A version)

In order to seal multiple sensor cables into

EXAxt 450, a special grommet is provided that

is designed to accommodate one, two or three

sensor cables (5 mm dia.) plus a liquid earth

cable (2.5 mm dia.). In the pack with thegrommet are blanking pieces to close any

unused holes. When correctly assembled, the

grommet maintains the IP66 and NEMA 4X

rating of the EXAxt 450 housing.

Note! The special grommet is intended to be

used to seal the multiple cables from the

Yokogawa flow fittings such as FF20.

The designated cables are WU20 sensor

cables, which are approximately 5 mm (0.2“) indiameter, and K1500FV liquid earth cables,

which are approximately 2.5 mm (0.1“) in

diameter.

For sensor systems using a single cable, like

the FU20 and the PR20, PD20, PF20 and

PS20, the standard gland will accommodate

the cable adequately. Single cables between

approximately 7 mm and 12 mm (0.28 “ and

0.47 “) can be sealed properly with these

glands and the standard tule.

3


15

IM 12B6B5-E-E



3-7-3. Sensor cable connections using

junction box (BA10) and extension

cable (WF10)

Where a convenient installation is not possible

using the standard cables between sensors and

transmitter, a junction box and extension cable

may be used. The Yokogawa BA10 junction boxand the WF10 extension cable should be used.

These items are manufactured to a very high

standard and are necessary to ensure that the

specifications of the system can be met. The

total cable length should not exceed 50 metres

(e.g. 5 m fixed cable and 45 m extension cable).

In case of systems using dual high impedance

sensors (e.g. Pfaudler 18), then the cable length

is restricted to 20 metres (fixed cable only, noextension with WF10).

14 Overall Screen

1 1

1

2

1

2

1 3

1 4

1 4

1 6

1 5

1 3

1 4

1 4

1 6

1 5

1 7

1 1

1 7

11 Red

12 Blue

15 Core 16 Screen

White Co-axial cable

13 Core 17 Screen

Brown Co-axial Cable

17 (screen)

14 (overall screen)

12 (blue)

11 (red)

13 (core)

16 (screen)

15 (core)

Co-axial cable(white)

Co-axial cable(brown)

11

12

13

14

15

16

17

11

12

13

14

15

16

17

BA10 WF10 EXA pH TRANSMITTER / CONVERTER

Figure 3-12. Connection of WF10 extension cable and BA10 junction box

16

IM 12B6B5-E-E



Extension cable may be purchased in bulk

quantities or in pre-finished lengths. In the case

of bulk quantities cut to length, then it is

necessary to terminate the cable as shown

below.

Termination procedure for WF10 cable.1. Slide 3 cm of heat shrink tube (9 x 1.5) over

the cable end to be terminated.

2. Strip 9 cm of the outer (black) insulating

material, taking care not to cut or damage

internal cores.

3. Remove loose copper screening, and cut off

the cotton packing threads as short as

possible.

4. Strip insulation from the last 3 cm of the

brown, and the white coaxial cores.

5. Extract the coaxial cores from the braid, and

trim off the black (low-noise) screening

material as short as possible.

6. Insulate the overall screen and the 2 coaxial

screens with suitable plastic tubing.

7. Strip and terminate all ends with suitable

(crimp) terminals and identify with numbers

as shown.

8. Finally shrink the overall heat shrink tube into

position.

Figure 3-13.a.

3 cm

heat shrink

9 cm

remove insulation

Figure 3-13.b.

Figure 3-13.c.

1112

17

15

16

1314

3


17

IM 12B6B5-E-E





4

ZERO value indicates the condition of the sensor.

If the value exceeds +/- 120 mV (or user defined

limits) an error message is displayed after

calibration and the calibration is rejected. The

trend of ZERO drift during the lifetime of the

sensor is used to predict the lifetime of the sensor.

ZERO can also be displayed in pH units and

then it represents the pH value where the

sensor output is 0 mV at 25 ºC. Go to:

Commissioning >> Measurement >>

Calibration Settings >> Zero and Slope

Units

4-3-4. Slope = calibrated efficiency of the

sensor unit in percentage of theoretical slope of

the sensor unit. The theoretical slope followsthe NERNST equation and is 59.16 mV/pH. The

SLOPE can be calibrated only after a two-point

calibration in buffer solutions with a different pH

value. A low slope indicates that the sensor is

not clean or it indicates a bad sensor. If the

calibrated slope exceeds the range 70-110%

(or user defined limits) then the calibration is

rejected and a error message is shown.

The SLOPE can also be displayed as mV/pH

value at 25 ºC if the user has defined this

variable as mV/pH in Commissioning >>

Measurement >> Calibration Settings >>

Zero and Slope Units

4-3-5. Sensor mV = the output of the sensor

unit prior to calibration and temperature

compensation. This value is important for

trouble shooting.

4-3-6. Reference impedance = the electrical

resistance of the liquid junction. The liquid junction forms the electolytical contact between

the reference element and the measuring

electrode, so it must be kept clean and filled

with conductive electrolyte. Otherwise the

measurement will suffer from instability, drift and

measuring errors. The electrical impedance is

one of the most important diagnostic tools for

keeping the measurement in good condition. If

the value exceeds a user defined limit (1000Ω -

1000kΩ) an error message will be displayed.

4-3-7. Last calibrated = the date on which

the last sensor calibration is done. The displayed

value of the ZERO is the result of this

calibration. The displayed value of Slope is not

necessarily calibrated on this date: only if the

last calibration was a 2-point calibration.

4-3-8. Calibration due = the date when the

calibration must be done according to thesettings of the maintenance timer. This is based

on scheduled maintenance procedures. The

maintenance intervals are set in menu: setup>>

Commissioning>> measurement setup>>

calibration settings >> limits and timing

4-3-9. Projected calibration = the date when

the predictive maintenance function expects that

recalibration of the sensor unit is necessary for

good measurement accuracy. The transmitterchecks the reference impedance every hour.

The user is notified when maintenance should

take place. Prior to calibration the sensor

should be well cleaned and rinsed.

4-3-10. Projected replacement = the datewhen the predictive maintenance function

expects that replacement of the sensor is

necessary for good measurement accuracy.

After each calibration the slope, zero and

reference impedance are logged. Aging of the

sensor can be detected from this data. The

observed trend is extra phated and thintrend

predicts when max devicions will be exceeded.

Good predictions are only achieved with good

calibration data. Prior to calibration the sensor

should always be well cleaned and rinsed and

the calibration procedures strictly observed.

OP E R A T I ON OF E X A x t P H 4 5 0 G

19

IM 12B6B5-E-E



4-3-11. Serial number = serial number of the

transmitter

4-3-12. Software revision = the revision level

of the software in the instrument

TROUBLE SHOOTINGIf you contact the local sales/ service

organization the serial number and software

revision is necessary information. Without that

information it is impossible to help you. It is also

very useful to report all the information that you

find on the zoom-in display.

4-3-13. HART Device revision

Sometimes the firmware of a device is updated

in a way that the communication file (HART DD)need revision too. In this case the revision level

is increased by one. The revision level of the

HART DD must match the revision level of the

Firmware. The revision level is expressed by the

first two characters of the filename.

The following files should be used when the

HART Device revision level is 2.

(0201.aot, 0201.fms, 0201.imp, 0201.sym)

4-3-14. Logbook

The EXAxt contains several logbooks to store

history information on events, changed settings

and calibrations. The logbooks have been

categorized to simplify the retrieval of this

information.

Calibration will give information of previous

calibrations. This logbook is useful as one now

can

1) Monitor the sensor performance over time.

2) Monitor the sensor(s) lifetime.

Sensor will give all history information on

parameter settings concerning the sensor(s).

The events logged in this logbook are user

definable. This is done in Commissioning >>

Configure Logbook >> Sensor Logbook.

Predictive maintenance. IIf the sensor

diagnostics of the EXAxt are enabled, the

diagnostics are saved into this logbook.

For the EXAxt PH450G, the reference

impedance (measured between the Liquid earth

and the reference electrode) is stored every

hour. This information can be used for

(predictive) maintenance schedules as the

impedance is a measure of fouling and the

sensor should be kept clean for best results.

Settings will give all history information onparameter settings concerning the analog

outputs (mA1/mA2) and contact (S1…S4). This

logbook is useful to trace back differences in

performance due to changed settings. The

events logged in this logbook are user definable.

This is done in Commissioning >> Configure

Logbook >> Settings Logbook – mA and/or

Settings Logbook – contact

mA1/mA2 shows all (dynamic) eventsconcerning the analog outputs

S1/S2/S3/S4 shows all (dynamic) events

concerning the contacts.

Each HMI screen can contain up to 5 events. As

the logbook can contain 50, one can access

previous events by selecting events page 1 to 10.

4-4. Information function

In this field an information sign , a warning

sign or a fail sign can appear. Pushing

this button, the user gets detailed information

about the status of the sensor or the instrument

if applicable.

See troubleshooting (chapter 8) for further details.

4-5. Setup-calibration & commissioning

By pressing the setup key, you get access

to the operating system of the transmitter based

on menus and submenus.

Browse through the list using the key

till you find the required menu and press

the key to enter this menu.

It is also possible to press on the or

symbol found beside the menu item.

4-6. Secondary-primary value display

switch

Pressing on this text block automatically

switches the secondary value to the main

display (Large font size).

25.0

20

IM 12B6B5-E-E



“HOME KEY” return to main display

“ R E T U R N

K E Y ” e x i t t o

p r e v i o u

s d i s p l a y

Main display

Primary setup display

Commisioning menu

Instrument in HOLD

4

4-7. Navigation of the menu structure

OP E R A T I ON OF E X A x t P H 4 5 0 G

21

IM 12B6B5-E-E

4-8. Setup Concentration mode

The concentration mode allows the user to

generate an analog output signal that is linear to

concentration units and to read the concentration

on the LCD in the units %, mg/l or ppt.

Example: PH450 is used as ORP analyser and

the output is linear to mg/l Free Chlorine.

As first step the table for mA1 must be filled in.

Then the concentration menu is opened: and

begin and end value of the scale are entered

Setup is completed.

The measured concentration is now displayed

on the top line of the LCD.



Menu Parameter Default Range

values min. max.

Manual Manual Temp. 25ºC, 77ºF -30ºC, -22ºF 140ºC, 284ºF

Temp. comp. Reference Temp. 25ºC, 77ºF 0ºC, 32ºF 100ºC, 212ºF

Temp. Coef T.C. pH 0.0 pH/ºC, 0.0 pH/ºF -0.1 pH/ºC, -0.06 pH/ºF 0.1 pH/ºC, 0.06 pH/ºF

Temp. Coef T.C. ORP 0.0 mV/ºC, 0.0 mV/ºF -10 mV/ºC, -6 mV/ºF 10 mV/ºC, 6 mV/ºF

Matrix Temp. Ranges – -30ºC, -22ºF 140ºC, 284ºF

Matrix pH Ranges – -2 pH 16 pH

Note!

‘Sensor type’ and ‘Measurement’ determine the rest of the HMI menu structure.

22

IM 12B6B5-E-E



5-1. Sensor setup

Sensor type: The sensor connection to the

terminals is determining the setting

of this parameter. Three selections

can be made here.pH: Only pH needs to be measured. The glass

electrode is connected to terminal 15 and

the reference is connected to terminal 13.

ORP: Only Redox needs to be measured. The

rH metal is connected to terminal 15 and the

reference (or glass) is connected to

terminal 13.

pH+: When pH and ORP should be pH+rH

ORP measured simultaneousely the glass

electrode is connected to terminal 15 andthe reference is connected to terminal 13.

The metal electrode is connected to

terminal 14. In this setup it is also possible

to measure rH, where the glass electrode

is used as a reference to the metal

measuring electrode. For rH

measurement the reference electrode is

not necessary. When left out, terminal 13

and 14 are shortcutted.

Note! For best results a Liquid Earth is connected

to terminal 14. If there is no LE terminal 13

and 14 are shortcutted and no sensor

diagnostics are possible. This setting

determines the menu structure thoughout

the instrument

5-2. Measurement setup

Measurement which process values.

This setting determines will be available for

monitoring and control.

5-3. Temperature setting

Temperature Element

Selection of the temperature sensor used for

compensation. The default selection is the

Pt1000 Ohm sensor, which gives excellent

precision with the two wire connections used.

The other options give the flexibility to use a very

wide range of other sensors.

Unit

Celcius or Fahrenheit temperature scales can be

selected to suit the user’s preference.

Manual temp., reference temp., temp.

coefficient and temp. ranges in the matrix are

re-calculated automatically to the new unit.

5-4. Temperature compensation Two types of methods can be used here.

Automatic when a temperature element is used.

Select one of the Temp. elements used. The

other is a manual set temperature, which

represent the temperature of the process. The

latter is used when temperature measurement is

difficult and temperatures do not vary much.

Reference Temperature

Choose a temperature to which the measuredpH value must be compensated. Normally 25°C

is used, therefore this temperature is chosen as

default value.

Process Temperature Compensation

TC

It is possible to adjust the compensation factor

directly. If the compensation factor of the

sample liquid is known from laboratory

experiments or has been previously determined,

it can be introduced here. Adjust the value

between –0.1 to 0.1 pH/ºC. In combination with

the reference temperature setting a linear

compensation function is obtained, suitable for

all kinds of chemical solutions.

Matrix

The EXAxt is equipped with a matrix type

algorithm for accurate temperature compensation

in various applications. Select the range as close

as possible to the actual temperature/pH range. The EXAxt will compensate by interpolation and

extrapolation. Consequently, there is no need for

a 100% coverage. See Appendix 3 for matrix

interpolation.

NEN6411

This is a NEN standard and applicable for many

applications. It’s used for pH compensation in

water applications using a glass electrode. The

calculation is base on Ultra Pure Water (UPW)

and is also valid for all strong acids and strong

bases. The main application is in demiwater and

boiler feed water/condensate.

5

ME N U S T R U C T U R E C OMMI S

S I ON I N G

23

IM 12B6B5-E-E

5. MENU STRUCTURE COMMISSIONING




values min. max.

Limits and timing Zero high 120 mV 0 mV 532.44 mV (relative to I.T.P.) 2.03 pH 0 pH 9 pH

Limits and timing. Zero low -120 mV -532.44 mV 0 mV (relative to I.T.P.) -2.03 pH 9 pH 0 pH

Limits and timing Slope high 110% 100% 110%Limits and timing Slope low 70% 70% 100%Limits and timing Stabilization time 5 sec. 2 sec. 30 sec.Limits and timing Calib. interval 250 days 1 day 250 daysBuffers Buffer table 1, 2, 3 Free programmable See appendix 1Zero/Slope/ITP Zero 0 mV Zero low Zero high

7 pH Zero low Zero highZero/Slope/ITP Slope 100% Slope low Slope high

59.16 mV/pH Slope low Slope highZero/Slope/ITP ITP 7 pH 0 pH 14 pHInput 1(or 2) Impedance High limit 200000 Ω 1000 Ω 1000000 ΩInput 1(or 2) Impedance Low limit 1000 Ω 1000 Ω 1000000 Ω

24

IM 12B6B5-E-E





mA2 similar structure to mA1


values min. max.

mA1 (control) Expire time 0.0 sec. 0 sec. 1800 sec.mA1 (output) Damping time 0.0 sec. 0 sec. 3000 sec.mA1 (simulate) Simulation perc. 50 % 0 % 100 %

P(ID)-control mA1 Setpoint 7 pH -inf +inf P(ID)-control mA2 Setpoint 25ºC/ºF -inf +inf P(ID)-control mA1 Range 1.00 pH -inf +inf P(ID)-control mA2 Range 10ºC/ºF -inf +inf

P-control mA1 Manual Reset 0 % 0 % 100 %PI(D)-control mA1 I-time 3600 sec. 1 sec. 3600 sec.P(I)D-control mA1 D-time 0 sec. 0 sec. 60 sec.

Linear mA1 0% Value 0 pH -inf +inf Linear mA2 0ºC/ºF -inf +inf

Linear mA1 100% value 14 pH -inf +inf Linear mA2 100ºC/ºF -inf +inf

Table Table mA1 see appendix 1 -2 pH 16 pH

26

IM 12B6B5-E-E



5-7. mA output setup

The general procedure is to first define the

function (control, output, simulate, off) of the

output and second the process parameter

associated to the output.

Available process parameters depend on

selected “sensor type” and “measurementsetup”.

Off : When an output is set off the output

is not used and will give an output of

4 mA

Control : A selection of P- PI- or PID control

Manual : Static output required to maintain

reset : equilibrium state with setpoint

Direction : Direct. If the process variable is too

high relative to the SP, the output of the controller is increased (direct

action).

: Reverse. If the process variable is

too high relative to the SP, the

output of the controller is decreased

(reverse action).

Output : Linear or non linear table output.

The table function allows the

configuration of an output curve by

21 steps (5% intervals). In the main

menu concentration can be selected

to set the concentration range.

Simulate : Percentage of output span.

Normal span of outputs are limited

from 3.8 to 20.5 mA

Burn Low or High will give an output of 3.6 resp.

21 mA in case of Fail situation.

Note! When leaving Commissioning, Hold

remains active until switched off manually. This is to avoid inappropriate actions

while setting up the measurement

Proportional control

Proportional Control action produces an output

signal that is proportional to the difference

between the Setpoint and the PV (deviation or

error). Proportional control amplifies the error to

motivate the process value towards the desired

setpoint. The output signal is represented as a

percentage of output (0-100%).

Proportional control will reduce but not eliminate

the steady state error . Therefore, proportional

Control action includes a Manual Reset . The

manual reset (percentage of output) is used to

eliminate the steady state error.

Note! Any changes (disturbances) in theprocess will re-introduce a steady state

error. Proportional control can also

produce excessive overshoot and

oscillation. Too much gain may result in

an unstable- or oscillating process. Too

little gain results in a sustained steady

state error. Gain = 1/Range. [PV units]

Integral control

Integral control is used to eliminate the steadystate error and any future process changes. It

will accumulate setpoint and process (load)

changes by continuing to adjust the output until

the error is eliminated. Small values of integral

term (I-time in seconds) provide quick

compensation, but increase overshoot. Usually,

the integral term is set to a maximum value that

provides a compromise between the three

system characteristics of: overshoot, settling

time, and the time necessary to cancel the

effects of static loading (process changes). The

integral term is provided with an anti windup

function. When the output of PI portion of the

controller is outside the control range (less than

-5% or greater than 105%), the I-part is frozen.

Derivative control

The control acts on the slope (rate of change) of

the process value, thereby minimizing

overshoot. It provides "rate" feedback, resulting

in more damping. High derivative gains can

increase the rizing time and settling time. It is

difficult to realize in practice because

differentiation leads to "noisy" signals.

5

SPPVe

+-

++

++

+-

e

Range

∫e dt1Ti

TddPVdt

z

Process

Controller

Actuator

Process


S I ON I N G

27

IM 12B6B5-E-E



S2, S3, S4 Similar structure to S1


values min. max.

PID-control S1 Setpoint 7pH -inf +inf PID-control S1 Range 1.00 pH 0.001 pH +inf P(ID)-control S1 Manual Reset 0% 0% 100%PI(D)-control S1 I-time 3600 sec. 1 sec. 3600 sec.P(I)D-control S1 D-time 0 sec. 0 sec. 60 sec.Duty cycle DC period time 10 sec. 1 sec. 1800 sec.Pulse freq. Max. pulse freq. 70 p/min. 1 p/min. 70 p/min.mA1 (simulate) Expire time 0.0 sec. 0 sec. 1800 sec. Alarm S1 Setpoint 13 pH (high) -inf +inf Alarm S2 Setpoint 1 pH (low) -inf +inf

Alarm Hysteresis 0.10 pH 0 pH +inf Alarm Delay time 0.2 sec. 0 sec. 1800 sec.Hold Fixed value mA1 12 mA 3.6 mA 21 mA Hold Fixed value mA2 12 mA 3.6 mA 21 mA

28

IM 12B6B5-E-E



IM 12B6B5-E-E

Expire time

If the output is over 100% for longer than the

expire time, the output will return to 0%.

Damping time

The response to a step input change reaches

approximately 90 percent of its final value withinthe damping time.

5-8. Contact output setput

S1/S2/S3/S4

Each Switch (contact) can have the following

functions.

1. Control : A selection of P- PI- or PID control

2. Alarm : Low or high value Limits monitoring

3. Hold : A hold contact is energised when

the instrument is in HOLD

4. Wash : See section 6-8

5. Fail : S4 is set as fail-safe contact.

6. Simulate: To test the operation of the

contact, simulate can be used. The

contact can be switched on or off

or a percentage of duty cycle can

be entered (DC period time)

7. Off : Switch is not used.

Configure hold

Hold is the procedure to set the outputs to a

known state when going into commissioning. Du-

ring commissioning HOLD is always enabled, out-

puts will have a fixed or last value. During calibra-

tion the same HOLD function applies. For calibra-

tion, it is up to the user if HOLD is enabled or not.

Lifetime contacts

One should note that the lifetime of the contacts

is limited (106) When these contacts are used for

control (pulse frequency or duty cycle with small

interval times) the lifetime of these contact

should be observed. On/Off control is preferred

over Pulse/duty cycle.

5

100%

0%set

pointprocessvalue

Direct

100%

0%set

pointprocessvalue

Reverse

range

range

manualreset

manualreset

Figure 5-2. Direct/Reverse action


S I ON I N G

29

Setpoint

Hys.

p H

off on off

Delay time Delay t imet (sec)

100

50

0

ton toff

50% 50%

% controller output

Range

Duty cycle

ton > 0.1 sec

Duty cycle

toff > 0.1 sec

Duty cycle

100

50

0

% controller output

Range

0.3 s

Maximum pulse frequency

50% pulse frequency

No pulses

0.3 s

Figure 5-3. Alarm contact (on/off control)

Figure 5-4. Duty cycle control

Figure 5-5. Pulse frequency control

power on power on

power downnormal opened

contact

activated

S1, S2, S3

S4



S2, S3, S4 Similar structure to S1


values min. max.

Generic wash settings Interval time 6 hour 0.1 hour 36 hourGeneric wash settings Wash time 0.5 min. 0.1 min. 10 min.Generic wash settings recovery time 0.5 min. 0.1 min. 10 min.Simulation Percentage 50% 0% 100%

(see chapter 6) for wash setup

30

IM 12B6B5-E-E



5-9. Fail

A fail contact is energized when a fail situation

occurs. Fail situations are configured in secton

5-10. For SOFT Fails the contact and the

display LED are pulsating. For HARD Fails the

contact and the display LED are energized

continuously.Only contact S4 is programmed as a fail-safe

contact. This means that contact S4 wil be

de-energized when a fail situation occurs.

The contact reacts to Hard Fails Only

The contact reacts to Hard and Soft Fails

5-10. Simulate

The contact can be switched on/off or a

percentage of output can be simulated. On/Off

enables the user to manually switch a contact

on or off. The percentage is an analogue value

and represents the on time per period.

The Duty cycle Period time (see figure 5-4) is

used as a period for percentage simulation.

Note that the (simulated) settings of the contacts

become visible in measuring mode and after

HOLD has ended c.q. has been overruled. A

warning is activated in case of a simulated

output contact.

Hard Fail Only

Hard + Soft Fail

5


S I ON I N G

31

IM 12B6B5-E-E



32

IM 12B6B5-E-E



5-11. Error configuration

Errors 1/3 ~ 3/3

Errors are intended to notify the user of any

unwanted situations. The user can determine

which situations should be clasified as:

FAIL, immediate action is required. The processvariable is not reliable.

WARN, the process variable processes by the

transmitter is still reliable at this moment, but

maintenance is required in the near future.

“FAIL” gives a flashing “FAIL” flag in the main

display. The contact configured as FAIL

(Commissioning >> output setup) will be

energized continuously. All the other contacts

are inhibited. Exception is the contactconfigured for ‘Wash’. Wash cycles are not

interupted as this might cause scaling/fouling to

the electrodes. A Fail signal is also transmitted

on the mA-outputs when enabled (burn

high/low). (Commissioning >> output setup)

“WARN” gives a flashing “WARN” flag in the

display. The contact configured as FAIL is

pulsed. All the other contacts are still functional,

and the transmitter continues to work normally.

A good example is a time-out warning that the

regular maintenance is due. The user is notified,

but it should not be used to shut down the

whole measurement.

5-12. Logbook configuration

General

Logbook is available to keep an electronic record

of events such as error messages, calibrations

and programmed data changes. By reference to

this log, users can for instance easily determinemaintenance or replacement schedules.

In “Configure Logbook” the user can select each

item he is interested in to be logged when the

event occurs. This can be done for three

separate logbooks. Each logbook can be erased

individually or all at once. Enable the ”Warn if

Logbook full” when you would like to be warned

when the logbook is almost full. The content of

the logbook(s) can also be retrieved from the

transmitter using the “EXAxt Configurator”

software package which can be downloaded

from the Yokogawa Europe website.

Flashing “Fail” flag in main display

Flashing “Warn” flag in main display

5


S I ON I N G

33

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values Low High

Hart Network address 0 0 15

34

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5-13. Advanced setup

Defaults

The functionality of the EXAxt allows to save and

load defaults to come to a known instrument

setting. The EXAxt has both factory and user

defined defaults.

After a “load default” the instrument will reset. The following parameters are not included in the

defaults

1. X-axis timing

2. Auto return (10 min / disabled)

3. Tag

4. Passwords

5. Date and time

6. Language

7. The contents of all logbooks8. HART parameters

(address, tag, descriptor, message)

Tag

A tag provides a symbolic reference to the

instrument and is defined to be unique throughout

the control system at one plant site. A tag can

contain up to 12 characters. If the instrument is

purchased with the /SCT option, the TAG is

pre-programmed with the specified tagnumber.

Passwords

Calibration and Commissioning may be

separately protected by a password. By default

both passwords are empty. Entering an empty

password results in disabling the password

check. A password can contain up to 8

characters. When a password is entered for the

calibration and commissioning a 4-digit operator

ID can be entered. One can also leave the ID

empty.

Date/time

The Logbooks and trend graph use the

clock/calendar as reference. The current date

and time is set here. The current time is

displayed in the third “zoom” menu.

Note! The fixed format is YYYY/MM/DD

HH:MM:SS

HART

The address of the EXAxt in a HART network

can be set. Valid addresses are 0...15.

FACTORY ADJUSTMENT

This menu is for service engineers only.

This section is protected by a password.

Attempting to change data in the factory

adjustment menu without the proper instructions

and equipment, can result in corruption of theinstrument setup, and will impair the

performance of the unit.

5


S I ON I N G

35

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values Low High

Y-axis pH low 0 pH -inf +inf Y-axis pH high 14 pH -inf +inf Y-axis ORP low -1500 mV -inf +inf Y-axis ORP high 1500 mV -inf +inf Y-axis rH low -inf -inf +inf Y-axis rH high +inf -inf +inf Y-axis Temp. low 0ºC, 0ºF -inf +inf Y-axis Temp. high 100ºC, 100ºF -inf +inf

36

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5-14. Display setup

Main display

The main display consists of three lines with

Process Values. Each line is user definable with

the restriction that each line should have a

different Process Value. The default settingscan be defined here. By pressing one of the

two smaller process values, this will become

the main process value in the main screen.

Autoreturn will cause the main display to go to

default setting.

See also 4-6 Secondary to Primary Value

display Switch.

Note! Configuration possibilities in the main and

secondary display lines are determined by thechoices made in the menu measurement

Measurement setup >> Measurement

Additional text

Each process value can be given an additional

text containing up to 12 characters per text.

This text is displayed on the main display next

to the process value. This way the user can

distinguish separate measurements.

X-axis timing

The time range of the trend graph can be set

from 15 minutes up to 14 days.

Y-axis limits

The ranges for each measurement need to be

set according the application.

Auto return

When Auto return is enabled, the transmitter

reverts to the measuring mode (main display)from anywhere in the configuration menus,

when no button is pressed during the set time

interval of 10 minutes.

5


S I ON I N G

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6-1. Calibration check with buffer solutions.

The following tips will help to produce a good

calibration.

1. Before starting a calibration, make sure theelectrode system is properly cleaned so that the

electrodes are fully functional. They must then

be rinsed with clean water to avoid

contamination of the calibration solution(s).

2. Always use fresh buffer solutions to avoid the

possibility of introducing errors from

contaminated or old solutions. Buffers supplied

as liquids have a limited shelf life, especially

alkaline buffers, which absorb CO2 from the air.

3. Yokogawa strongly recommends NIST (primary) buffer standards in order to ensure the

best accuracy and best buffer capacity is

available. Commercially adjusted buffers (e.g.

7.00, 9.00 or 10.00 pH) are a compromise as a

standard, and are often supplied without the

temperature dependency curve. Their stability

will never be as good as NIST solutions.

Note! NIST (formerly NBS) buffers are available

as consumable items from any Yokogawa sales

office under the following part numbers:

6C232 4.01 pH at 25°C

6C237 6.87 pH at 25°C

6C236 9.18 pH at 25°C

A box contains 5 packets of powder. Each

packet makes 200 ml of solution when

dissolved in good quality distilled water.

Always ensure that the sensors are properly

conditioned, clean and filled with the correct

electrolyte solution (if appropriate) before startinga calibration. Refer to section 7 (Maintenance),

and to the sensor instructions for details.

6-2. Manual calibration mode

The unit is adjusted to agree with the value of a

known solution. This may be a buffer solution or

a known process sample. The user determines

the pH value, the temperature influence and the

stability.

1- A single point can be set to adjust only

the zero (asymmetry).

2- A second point can be set to determine

the slope (sensitivity).

6-3. Automatic calibration mode

The PH450G will provide prompts to aid the

user to make a good calibration. High quality

buffer solutions must be used for best results.

The user selects the buffer type that he is usingin the calibration menu. The buffer set is

selected in Commissioning >> Measurement

setup >> Calibration setting>> Buffers

See also Appendix 1.

The PH450G uses temperature sensor input to

determine the exact buffer values.

The EXAxt also determines the stability (drift)

and will reject the new calibration data if it is

outside limits. The PH450G records the values internally, and

uses them to calculate the final calibration.

1- A single point can be set to adjust only

the zero (asymmetry).

2- A second point can be set to determine

the slope (sensitivity).

38

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6. CALIBRATION



6

When the right buffer tables are entered,

automatic calibration is the easiest and most

reliable calibration method to use.

The calibration is performed in several steps,

each clearly indicated by the user interface.

Each measurement point needs to be stable

before proceeding. The parameters for thisstability check are set in Commissioning >>

Calibration pH >> Limits and timing

We advice to leave the sensors for 3~5 minutes

in the buffer solution before proceeding, even

when the measurement is stable. This will give

reliable and accurate calibration results.

6-4. Sample calibration mode

This mode is used first to record aninstantaneous value for a grab sample. The

sample value is held in memory, and normal

measurement and control can continue, while

the sample is analyzed. Following the analysis

re-enter the "Sample" calibration mode. The

original value (from memory) is displayed, The

recorded reading is simply adjusted to agree

with the analyzed value. The sample mode

eliminates the calculation usually needed for this

kind of calibration. A sample calibration is a

single (zero) point calibration.

6-5. Temperature calibration

In order to make the most accurate

measurements, it is important to have a precise

temperature measurement. Measure the

temperature with a high precision thermometer.

Adjust the sensor reading accordingly. For best

accuracy this should be done as near to the

normal operating temperature as possible.

ORP & rH calibration modes

6-6. ORP & rH calibration

The calibration modes for ORP or rH are the

"Manual" and the "Sample" modes.

"Manual" calibration can be used for either

single or two point calibrations.

"Sample" calibration is only a single point as it is

with in pH measurement.

Note! The non-availability of well defined buffer

solutions for ORP and rH eliminates the

automatic calibration option.

Refer to the user manual of the ORP electrode

for the proper calibration method.

6-7. Operation of hold function during

calibration

EXAxt PH450G has a HOLD function that will

suspend the operation of the control/alarm

relays and mA-outputs.

During calibration, the user may choose to

enable HOLD so that the output signals arefrozen to a “last” or “fixed” value. Some users

will choose to leave the outputs "live" to record

the calibration event. This has implications for

pharmaceutical manufacture, for example,

where an independent record of calibrations is

mandatory. Press HOLD button on mainscreen,

to remove the HOLD. The route for HOLD setup

is Commissioning >> Output setup>>

Configure Hold

6-8. Contact output setup

Wash

Wash functionality is more than activating the

cleaning system. Wash can be seen as an

interruption of the normal measuring mode to

clean the electrode system. The wash cycle first

cleans the sensor system (either chemical or

mechanical) during "wash time” (T W). Next the

sensor system is left to recover during "wash

recovery time” (T R). After the sensor system is

recovered, the wash cycle has ended and trans-mitter returns to the normal measuring mode.

The input contact is always enabled when an

output contact is configured as wash. The input

contact can be used to enable a wash when a

high impedance error occurs on the reference

electrode. Then one wash cycle is started.

Hold during wash

When enabled, the mA-outputs will be frozen to

a pre-defined “last” or “fixed” value. All contacts

are de-energized except the one(s) configured

as “wash” contact. Disabled, mA-outputs and

contacts will not be affected by wash cycles.

C A L I B R A T I ON

39

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Termination of a wash cycle

The user can decide to terminate the current

wash cycle. This is done in the main screen (all

other screens are deactivated) by pressing the

wash flag (once or twice). The wash cycle has

two time intervals (T W and T R) and depending on

the moment of pressing the "wash" flag thecurrent interval is ended (see fig. 6-1)

Note! Recovery time is intended to let the

sensor system recover to "Normal"

process conditions.

Manual wash

When enabled in the “generic wash setings”,

wash cycles can be activated manually via the

user interface: Calibration/Wash >> Start

manual wash cycle or via an input contact (if provided for.)

Continuous wash during sample/hold

measurement

Some processes scale the electrodes in such a

way that the electrodes need continuous wash

in order to keep on performing well. In this

configuration, a "recovery time" and a "interval

time" interrupt the continuous wash (cleaning).

The continuous wash cycle is started the

moment "Continuous wash" is enabled. First

with "measuring mode” which has the duration

of “wash time", followed by the “wash mode”

which has the duration of “interval time”.

The "interval time" and "wash time" are

reversed!

The wash cycle is terminated the same wayas described above; pressing the wash flag in

the main display (once or twice). When the

cycle is terminated "Continuous wash" should

be re-enabled to start the wash cycle.

Note! When this setup is chosen special care

should be taken in reference to scaling

when the wash cycle is terminated.

Note! In this configuration manual wash is notapplicable.

Diagnostics

The response time is a good diagnostic tool to

see the condition of the electrode system.

During the recovery time the response is

monitored and an error is generated when the

"half time value" was not reached within 1/3 of

the recovery time.

Input Contact

The input contact is always enabled when an

output contact is configured as wash. The input

contact can be used to enable a wash after the

detection of an Impedance High error.

MeasuringMode

WashMode

RecoveryMode

W a s h

t i m e

T W e n

d e d

W a

s h f l a g

p r e s

s e d

R e c o v e r y

t i m e T R

e n d e d

W a s h

f l a g p r e s

s e d

WASH

HOLDOL

WASH SH

HOLDOL

Interval time ended

Figure 6-1. Wash cycle

40

IM 12B6B5-E-E

Figure 6-2. Chemical cleaning of sensors

pH

7.0

4.5

2.0

GOOD SENSOR

AGED SENSOR

TW TR

1 / 3TR time



41

IM 12B6B5-E-E

7-1. Periodic maintenance

The transmitter requires very little periodic

maintenance, except to make sure the front

window is kept clean in order to permit a clear view

of the display and allow proper operation of thetouchscreen. If the window becomes soiled, clean

it using a soft damp cloth or soft tissue. To deal

with more stubborn stains, a neutral detergent

may be used.

When you must open the front cover and/or

glands, make sure that the seals are clean and

correctly fitted when the unit is re-assembled in

order to maintain the housing’s weatherproof

integrity against water and water vapor. The pHmeasurement uses high impedance sensors and

may otherwise be prone to problems caused by

exposure of the circuitry to condensation.

Note! Never use harsh chemicals or solvents. In

the event that the window does become

heavily stained or scratched, refer to the

parts list (Chapter 10) for replacement

part numbers.

Battery

The EXAxt transmitter contains a logbook

feature that uses a clock to provide the timings.

The instrument contains a lithium cell (battery) to

support the clock function when the power is

switched off. The cell has an expected working

life of 10 years. Should this cell need to be

replaced, contact your nearest Yokogawa

service center.

Fuse There is a circuit board mounted fuse protecting

the instrument. If you suspect that this needs to

be replaced, contact your nearest Yokogawa

service center.

7-2. Periodic maintenance of the sensor

Note! Maintenance advice listed here is

intentionally general in nature. Sensor

maintenance is highly application specific.

To perform correctly, pH sensors should be

clean. This may be an obvious statement, but it

has some implications for routine maintenance.

The user should consider the reason behind a

drift seen in a pH sensor system, rather than to

blindly recalibrate frequently, and hope to thus

minimize the errors. Most drift in pH systems

can be traced to fouling or deposits of somesort building up on the sensor. It is often the

case that a simple frequent cleaning regime can

replace a (too) frequent calibration with the

associated saving in labor and costly calibration

solutions.

Neutralization processes where lime or soda is

used to raise the pH are well known for causing

coatings and blocking reference junctions with

the insoluble hydroxides that are precipitated. Insuch an application, daily washing of the sensors

in a dilute acid will yield a far better performance

than a daily buffer calibration. It will also take a

fraction of the time.

Each application should be judged on it's own

merits, some will have greasy deposits that will

need a soapy solution to clean, some may even

require organic solvents to remove resinous

deposits. In any case, avoid harsh chemicals like

concentrated acids and abrasive cleaners as

these will destroy the conditioning of the

sensors, and will require a re-hydration period

before full function is restored. After cleaning the

sensors, and prior to a calibration, always rinse

thoroughly in distilled water to ensure that there

is no residue of the cleaning medium to

contaminate your calibration solution.

Note! Some applications will poison simple

sensors with non-reversible chemicalchanges. These systems do not improve

with cleaning. If you suspect that your

system is one of these, contact your local

Yokogawa sales office or representative

for advice. An alternative sensor type will

improve the performance.

7

MA I N

T E N A N C E

7. MAINTENANCE



42

IM 12B6B5-E-E

Where a refillable (flowing electrolyte) reference

system is employed, make sure that the

reservoir is kept topped up. The rate of

electrolyte consumption will again be process

dependent, so experience will show how often

you must refill. Pressurized systems need to be

regularly checked to ensure that the pressure isadequate.

Periodic re-calibration of the sensor system is

necessary to ensure best accuracy. This takes

into account the aging of the sensors, and the

non-recoverable changes that take place.

These processes are slow, however. If frequent

re-calibration is needed, it is usually because the

cleaning technique is not effective, the

calibration is not well executed or the pHreadings are temperature dependent. Monthly

calibrations should be sufficient for most

applications.

If a film remains on the pH sensor after

cleaning, or if the reference junction is partly

plugged, measuring errors can be interpreted

as a need for re-calibration. Because these

changes are reversible with correct cleaning, or

adjustment of the electrolyte flow through the

junction, make sure that these items are correct

before re-calibrating the system.



43

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8-1. General

The EXAxt is a microprocessor-based

transmitter that performs continuous self-

diagnostics to verify that it is working correctly.

Error messages resulting from faults in themicro-processor systems itself are monitored.

Incorrect programming by the user will also result

in an error, explained in a message, so that the

fault can be corrected according to the limits set

in the operating structure. The EXAxt also

checks the sensor system to establish whether

it is still functioning properly.

In the main display screen is a "Status

Information" button that will show

For information

For warning - a potential problem is

diagnosed, and the system should be checked.

For FAIL, when the diagnostics have confirmed

a problem, and the system must be checked.

This button gives access to a status report

page, where "The most applicable error" will

be displayed. ("No errors" is displayed during

proper operation)

Explanation >> Description or error message

and possible remedies

Advanced troubleshooting >> Error code

screen that is used in conjunction with the

service manual. This data may also be needed

in the event that you request assistance from a

Yokogawa service department.

What follows is a brief outline of the EXAxt

troubleshooting procedures including possible

causes and remedies.

8-2. Calibration check

The EXAxt PH450G transmitter incorporates a

diagnostic check of the adjusted slope or zero

value during calibration. If the adjusted value

stays within the configured limits, it is accepted,

otherwise, the unit generates an error message,

and the calibration is rejected.

8-3. Predictive maintenance

EXAxt has a unique prediction feature.

Calibration, and reference impedance data are

stored in software data logbooks. This data is

then used to calculate a prediction formaintenance purposes.

See section 4-3-9 and 4-3-10.

8-4. Error displays and actions

All errors are shown in the "Main Display"

screen, however, the EXAxt makes a distinction

between diagnostic findings. The error

messages may be set to OFF, WARN or FAIL.

For process conditions where a particular

diagnostic may not be appropriate, the settingOFF is used. FAIL gives a display indication only

of that the system has a problem and inhibits

the relay control action, and can be set to

trigger the "Burn" function. "Burn-up or

Burn-down" drives the mA output signal to

21 mA or 3.6 mA respectively.

8.5. Contrast adjustment

During the life of the analyzer the contrast of

the display may fade. The contrast can be

adjusted using the potentiometer on the

backside of the LCD board. The position is

shown on the picture below. For units delivered

prior to April 2006 the potentiometer is placed

behind the little hole in the LCD bracket as

shown in figure 3.4 on page 6.

8

T R O U B L E S H O OT I N G

8. TROUBLESHOOTING



44

IM 12B6B5-E-E

9. QUALITY INSPECTION STANDARD (QIS)

Before shipping any instrument, Yokogawa submits all their instruments to a series of functional

tests. The results of these tests are printed on a standard Test Certificate form and are shipped with

the instrument. This chapter provides additional information what tests are performed and how to

interpret the results.

1. Instrument description

Each instrument is uniquely defined by the Serial Number. The SN is shown on the fourth "zoom"

screen of the transmitter.

Sequence number

Automated Test Equipment number (1~3)

Date: 2002 P January 1

2003 R February 22004 S March 3

2005 T April 4

2006 U May 5

2007 V June 6

2008 W July 7

2009 X August 8

2010 A September 9

2011 B October A

2012 C November B

2013 D December C

Tag: This TAG should be unique throughout the plant and correspond to the TAG on top of the

transmitter. The TAG is (pre-)defined by the user.

2. Safety tests

This instruments is designed according the IEC 61010C-1, the safety requirements for electrical

equipment for measurement control. To ensure that the design and methods of construction used

provide adequate protection for the operator against electrical shock and against fire, its mandatory

that each instrument is tested for the bonding between protection earth and all accessible

conductive parts on the outside of the instrument, the insulation/dielectric strength between the

hazardous live parts at one side and the protection earth and low voltage parts at the other side.

3. Functional tests

• Visual check during start up

• The Serial number is set (see instrument description)

• The voltage between terminals 11 & 12 is checked. This is required for temperature measurement.

• Burn high (fail annunciation) for mA-output 1 (61,62) and mA-output 2 (65,66) is tested (>21mA).

• Input contact switch (terminals 21 and 22) is checked.

• Contacts (terminals 31,32,33 / 41,42,43 / 51,52,53 / 71,72,73) are checked.

Communication test HART®

During the complete test procedure, the automated test equipment uses HART® communication to

operate the instrument. When there are no signs of errors in the HART® signals, this test is

completed.

R4 3 031



Date/Time test

The current Date/Time is set.

4. Sensor input, linearity and accuracy tests

After the instrument is initialized, the linearity and accuracy is tested. This is done by connecting a

mV-source between input 1 (terminal 15) and 14 (Liquid earth) and subsequently between input 2

(terminal 13) and 14 (liquid earth). For this test the Zero is set to 0 mV and the Slope is set to 100%(59.16 mV/pH.) The pH values on the Test certificate can be converted to mV values (mV-source

input) by subtract the given pH value from 7 and multiplying this value with 59.16 mV/pH.

Example: 10 pH corresponds with (7-10) * 59.16 = -177.48 mV

Figure 9-1. Connection diagram for test procedure

5. Temperature accuracy tests

The EXAxt supports a number of temperature elements. All these elements are initialized and tested

for accuracy. The resistor decade box is set to the following impedance values to accurately simulate

the temperature element impedance.

-10 ºC 25 ºC 75 ºC 120 ºC

Pt1000 960.9 Ω 1097.4 v 1290.0 Ω 1460.6 Ω

Pt100 96.1 Ω 109.7 Ω 129.0 Ω 146.1Ω

5k1 4457.4 Ω 5100.0 Ω 6018.0 Ω 6884.2 Ω

3kBalco 2538.0 Ω 3000.0 Ω 3660.0 Ω 4254.0 Ω

8k55 47000.0 Ω 8550.0 Ω 1263.0 Ω 343.0 Ω

350 309.0 Ω 350.0 Ω 408.6 Ω 461.4 Ω

PTC10k 8827.0 Ω 10000.0 Ω 11680.0 Ω 13189.0 Ω

6k8 5943.2 Ω 6800.0 Ω 8024.0 Ω 9125.6 Ω

6. Impedance

Part of the diagnostics of the EXAxt, the impedance of Input 1 and input 2 are measured. For glass

electrodes the jumper is removed and the impedance should be over 100kΩ. This limit value is

checked. For metal- and/or reference electrodes the jumper should be installed and the impedance is

measured accurately (detect fouling, scaling, etc.).

7. mA-output accuracy

The EXAxt simulates a number of mA-output values. The accuracy of both mA-outputs is checked

with a load of 300Ω. The ripple voltage over the 300Ω load is measured and should be within 30mV

(RMS). With a load of 600Ω the instrument should still be able to transmit a signal of 22mA (no signal

drop with maximum load).

45

IM 12B6B5-E-E

PH450

mV Source

11

12

13

14

15

16

17

+ 61

- 62

63

+ 65

- 66

A

A 300Ω

300Ω

1 2 3

AC

neutralphase

DC

-+

9

T E S T C E R T I F I C A T E



46

IM 12B6B5-E-E

8. Overall accuracy tests

All separate accuracy tests are performed. As all these accuracies will accumulate (or influence each

other), an overall accuracy test is performed.

Note! The instrument is set to default values as certain settings like temperature compensation will

alter the transmitted signal. If one decides to perform an overall test, one can save current

settings as user defined defaults before proceeding. Afterwards these settings can berestored from memory.

Note that we specify the environmental influences to our instruments in our specifications.

These should be taken into account when performing an overall accuracy test.

9. Approval

All our instruments are designed and manufactured to the highest standards. All tests are performed

under controlled ambient temperature and humidity by well trained employees.



47

IM 12B6B5-E-E

9

T E S T C E R T I F I C A T E



48

IM 12B6B5-E-E

10. SPARE PARTS

Item Description Partnr

1a Power board AC version K1548AF

1b Power board DC version K1548DF

2 Pre&dig board PH version K1548FE

3 LCD module *) K1548ED4 LCD zifcable K1548JC

5 Power flatcable K1548JD

6a Fuse AC version (10 pcs.) K1548EF

6b Fuse DC version (10 pcs.) K1548AM

7 Cover assembly with gasket, screws and hingepins K1548MY

8 Glandset (6 pcs. M20) plus 1 tule and Grommetset K1548MV

9 Tagplate blank (incl. 2x M3) K1548MT

10 Panelmounting kit K1541KR

11 Pipe/wall mounting kit K1542KW

12 Flashloader kit K1548FU

*) K1548EC= spare LCD for units delivered before may 2006 (SN=U5)

K1548ED= spare LCD for units delivered after April 2006 and for all models 450- -U

K1548EE= conversion kit for replacement of K1548EC by K1548ED. The kit includes LCD unit and

brackets. New Firmware version must be downloaded with Flash unit K1548FU.

(7) Front Cover assembly

(2) Pre&Dig Board

(4) LCD Zifcable

(9) Tag Plate

(5) Power Flatcable

(1) power board

(8) glandset

(6) fuse (at the backside)

(3) LCD Module



49

IM 12B6B5-E-E

11. SOFTWARE HISTORY

Software version 1.10

• Service menu moved to Advanced Setup - Factory Adjustment

• introduced Service password that is unique per device (derived from S/N via an algorithm)

• increased font size for unit in main screen

• added the possibility to enter a four digit Operator-ID after entering the Calibration andCommissioning password; this ID will be logged

• HOLD flag has been given a ‘button’ look (can be pressed to deactivate HOLD)

• After leaving Setup, the HOLD status is made equal to the situation before entering Setup

• routing tags in Output Configuration screen longer then 12 characters will be shown correctly

• result of Predictive Maintenance calculation shown as time frame (instead of date)

• improved detection, analysis and handling of error 121 (unstable measurement)

• improved error analysis (Eeprom error generated) for a completely uninitialized device

• system errors during (re)start of device are now logged

• fixed reset problem due to watchdog error caused by a full logbook (from 1.01)

• concentration measurement added to PH450G, via mA-output table• Input Contact for pH is always enabled if an output contact is configured as Wash

• added the function to execute a wash cycle after detection of an impedance high error

• Error “Impedance 2 too low” : default value is OFF

• fixed bug where a clearance of User Defined buffers resulted in a software crash

• fixed bug where the minimum span between buffers appeared to be 2 instead of 1 pH

Software version 1.20

• Firmware update for new LCD (April 2006)

1 0

1 1

S OF T WA R E

H I S T OR Y

S

P A R E

P

A R T S



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IM 12B6B5-E-E

APPENDICES

APPENDIX 1, BUFFER TABLES

NIST (IEC 746-2)/DIN 19266°C 0 5 10 15 20 25 30 35 38 40 45 50 55 60 70 80 90 95

1,68 pH 1.668 1.670 1.672 1.675 1.679 1.683 1.688 1.691 1.694 1.700 1.707 1.715 1.723 1.743 1.766 1.792 1.8064,01 pH 4.003 3.999 3.998 3.999 4.002 4.008 4.015 4.024 4.030 4.035 4.047 4.060 4.075 4.091 4.126 4.164 4.205 4.227

6,87 pH 6.984 6.951 6.923 6.900 6.881 6.865 6.853 6.844 6.840 6.838 6.834 6.833 6.834 6.836 6.845 6.859 6.877 6.886

9,18 pH 9.464 9.395 9.332 9.276 9.225 9.180 9.139 9.102 9.081 9.068 9.038 9.011 8.985 8.962 8.921 8.885 8.850 8.833

DIN 19267 (German buffers) so called: technical buffer solutions°C 0 10 20 25 30 40 50 60 70 80 90

4,65 pH DIN 4.670 4.660 4.650 4.650 4.650 4.660 4.680 4.700 4.720 4.750 4.790

6,79 pH DIN 6.890 6.840 6.800 6.790 6.780 6.760 6.760 6.760 6.760 6.780 6.800

9,23 pH DIN 9.480 9.370 9.270 9.230 9.180 9.090 9.000 8.920 8.880 8.850 8.820

US technical buffers°C 0 5 10 15 20 25 30 35 40 45 50 55 60

4.0 pH US 4.000 3.998 3.997 3.998 4.001 4.005 4.001 4.018 4.027 4.038 4.050 4.064 4.0807.0 pH US 7.120 7.090 7.060 7.040 7.020 7.000 6.990 6.980 6.988 6.978 6.970 6.890 6.980

10.0 pH US 10.317 10.245 10.179 10.118 10.062 10.012 9.966 9.926 9.889 9.856 9.828 9.828 9.828

FREE PROGRAMMABLE (Default settings based on rounded NIST values).°C 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80

buffer 4 4.00 4.00 4.00 4.00 4.00 4.01 4.02 4.02 4.04 4.05 4.06 4.08 4.09 4.11 4.13 4.15 4.16

buffer 7 6.98 6.95 6.92 6.90 6.88 6.87 6.85 6.84 6.84 6.83 6.83 6.83 6.84 6.84 6.85 6.85 6.86

buffer 9 9.46 9.40 9.33 9.28 9.23 9.18 9.14 9.10 9.07 9.04 9.01 8.99 8.96 8.94 8.92 8.90 8.89

The freely programmable table is populated with a basic set of data to provide a start for the

user configuration. This table is intended for the user to be able to choose his buffer solutions to suit

his own preference. The data concerning the pH temperature characteristic will need to be obtained

from the supplier of the buffers.

Note: Yokogawa recommend the use of NIST (primary buffer standards) rather than buffers which

have been adjusted by the addition of acid or alkaline materials to the buffer composition. In this way

the customer gets a recognized standard, as well as the best buffer capacity (the ability to resist pH

change with contamination).

Packs of NIST buffer powders are available from all Yokogawa sales offices and representatives.

Each pack contains 5 sachets of powder, each sufficient to make 200 ml of solution when dissolved

in good quality distilled water. The part numbers to order are as follows:

Pack of 5 sachets buffer powder 4.01 pH at 25ºC Part No. 6C232Pack of 5 sachets buffer powder 6.87 pH at 25ºC Part No. 6C237

Pack of 5 sachets buffer powder 9.18 pH at 25ºC Part No. 6C236

Defaults for matrix temperature compensation Tref T1 T2 T3 T4 T5

25 ºC 5.0 ºC 25.0 ºC 45.0 ºC 65.0 ºC 85.0 ºC

Solution 1 6.40 pH 6.42 pH 6.40 pH 6.34 pH 6.23 pH 6.11 pH





Defaults for mA-output table% 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

pH 0.0 0.7 1.4 2.1 2.8 3.5 4.2 4.9 5.6 6.3 7.0 7.7 8.4 9.1 9.8 10.5 11.2 11.9 12.6 13.3 14.0



51

IM 12B6B5-E-E

Online menu Level 1 menu Level 2 menu Level 3 menu Level 4 menu

Process values Primary value (pH)*

Secondary value (Temp.)

Tertiary value (ORP/rH)*

Zoom Zoom sensor Zero*

Slope*

Sensor mV*

ORP Zero*

ORP Slope*

ORP Sensor mV*

RH Zero*

RH Slope*RH Sensor mV*

impedance 1*

impedance 2*

Zoom outputs mA1 value

mA2 value

S1 perc.

S2 perc.

S3 perc.

S4 perc.

Zoom device Serial number

Software Revision

Device Revision

DD Revision

Logbook Sensor data Calibration

Sensor

Pred.Maint

Output data Settings

mA1

mA2

S1

S2

S3

S4

APPENDIX 2, HART HHT (275/375) MENU STRUCTURE

A

A P P E N D I C E S



52


Most appl. Error Error description / remedy

Calib / Wash pH 1pt Calibration*

ORP 1pt Calibration*rH 1pt Calibration*

pH Sample Calib.*

ORP Sample Calib.*

rH Sample Calib.*

Temp. Calibration

Manual Wash

Hold Hold Instrument

Hold Outputs

Hold Off

Commissioning Sensor setup Sensor type

Measurement setup Meas type*

Temp settings Temp sensor

Temp unit

Temp compensation Temp comp

Man value*

Ref temp

Comp method* TC*

ORP comp method*

ORP TC*

Calib. settings Zero/Slope units* Zero unit

Slope unit

Limits and timing Zero hi lim*

Zero lo lim*

Slope hi lim*

Slope lo lim*

ORP Zero hi lim*

ORP Zero lo lim*

ORP Slope hi lim*

ORP Slope lo lim*

rH Zero hi lim*

rH Zero lo lim*

rH Slope hi lim*

rH Slope lo lim*

Stab time

Cal int

IM 12B6B5-E-E





54


Commissioning Output setup HOLD setup HOLD L/F

mA1 fixed*

mA2 fixed*

Hold dur. cal/wash

Error config Configure error

Off/Warn/Fail

Logbook config Sensor logbook

mA logbook

Contact logbook

Erase logbook Calibration

Sensor

Predictive. Maint. All logbooks

Warn logbook full

Loop test

Basic setup Tag

Distributor

Model

Device information Date

Descriptor

MessagePoll addr

Num resp preams

Review Model

Distributor

Write protect

Manufacturer

Dev id

Tag

Descriptor

Message

Date

Universal rev

Fld dev rev

Sofware rev

Poll addr

Num req preams

IM 12B6B5-E-E



The matrix can be cleared before entering new

values. Next new matrix values can be enteredas described above. The EXAxt can interpolate

the matrix. During this process it will check if

the matrix is completely ascending/descending.

This is necessary as otherwise the lookup

function can give two results for one

temperature. If an error is found, the EXAxt will

specify the location of the error as shown in the

user interface screen above.

The backspace key should be used for deletingan individual matrix value.

An empty value is shown as

APPENDIX 3, TEMPERATURE COMPENSATION MATRIX

1. A minimum number of values is required to make interpolation possible.

The highlighted values markes as are mandatory to enter.

Tref T1 T2 T3 T4 T5

Sol1 S1Tr S1T1 S1T5

Sol2

Sol3

Sol4

Sol5 S5Tr S5T1 S5T5

2. Tref (reference temperature) is defined in the Temperature Compensation menu.

If Tref is between T1 and T5 then the value of Tref needs to be entered as T2 or T3 or T4.

Tref T1 T2 T3 T4 T5

Sol1 S1Tr S1T1 S1T5

Sol2

Sol3

Sol4

Sol5 S5Tr S5T1 S5T5

3. For every SxTx that is entered the following values become mandatory to enter:

SxTr, SxT1, SxT5 and Tx

Tref T1 T2 T3 T4 T5

Sol1 S1Tr S1T1 S1T5

Sol2

Sol3 SxTr SxT1 SxTx SxT5

Sol4

Sol5 S5Tr S5T1 S5T5

A

A P P E N D I C E S

55



YOKOGAWA CORPORATION OF AMERICA 2 Dart RoadNewnan GA 30265United StatesTel. (1)-770-253-7000Fax (1)-770-251-2088www.yokogawa.com/us

YOKOGAWA HEADQUARTERS9-32, Nakacho 2-chome,MusashinoshiTokyo 180JapanTel. (81)-422-52-5535Fax (81)-422-55-1202www.yokogawa.com

Yokogawa has anextensive sales and

distribution network.

Please refer to the

European website

(www.yokogawa.com/eu)

to contact your nearest

representative.

Documents

Yokogawa PH450G Transmitter